Posts Tagged ‘chimpanzees’

CBC reports on a recent paper suggesting that chimpanzees, like humans, can transmit elements of material culture between each other. We all learn, and share.

It’s not just humans who want the latest gadget. Wild chimpanzees that see a friend making and using a nifty new kind of tool are likely to make one for themselves, scientists report.

“Our study adds new evidence supporting the hypothesis that some of the behavioural diversity seen in wild chimpanzees is the result of social transmission and can therefore be interpreted as cultural,” an international research team writes today in the journal PLOS Biology.

The findings suggest that the ability of individuals to learn from one another originated long ago in a common ancestor of chimpanzees and humans, the researchers add.

“This study tells us that chimpanzee culture changes over time, little by little, by building on previous knowledge found within the community,” said Thibaud Gruber, a co-author of the study, in a statement. “This is probably how our early ancestors’ cultures also changed over time.”

Scientists already knew that chimpanzees in different groups have certain behaviours unique to their group, such as using a particular kind of tool. They suspected that wild chimpanzees learn those behaviours from other chimpanzees within their group, as scientists have observed in captive chimps. But they could never be sure.

The new study documents the spread of two new behaviours among chimpanzees living in Uganda’s Budongo Forest. It shows that chimps learned one of them — the making and use of a new tool called a moss sponge — by observing other chimps who had already adopted the behaviour. Chimps dip the tool in water and then put it in their mouth to drink.

Wired‘s Brandon Keim reports on claims by scientists to have observed what might be proto-language among chimpanzees, one based on gestures.

It will be interesting to watch this develop. It is noteworthy that chimpanzees can’t speak because they’re physically unable to, and that other primates like the famous Koko the gorilla have mastered sign language. What was going on unnoticed in the wild?

Scientists have described the communications of chimpanzees and bonobos in new and unsurpassed detail, offering a lexicon for our closest living relatives and even a glimpse into the origins of human language.

The research, contained in two new studies published July 3 in Current Biology, focuses on physical gestures. These are the primary form of communication in bonobos and chimps, used more readily than vocalizations.

One study describes how a certain bonobo gesture conveys an informational complexity not previously observed in non-human great apes. The other study identifies the meanings of no fewer than 36 chimpanzee gestures.

“What we’ve shown is a very rich system of many different meanings,” said primatologist Richard Byrne of Scotland’s University of St. Andrews, co-author of the chimpanzee study. “We have the closest thing to human language that you can see in nature.”

Byrne’s co-author, fellow University of St. Andrews primatologist Catherine Hobaiter, spent 18 months observing a group of chimpanzees in the Budongo Forest Reserve in western Kenya. Hobaiter painstakingly documented more than 4,500 gestures in 3,400 incidents of chimp-to-chimp gesturing, noting both the motions used and the responses of nearby chimps.

Subsequent statistical analysis boiled those observations down to 36 established gestures and 15 clear-cut meanings. (Multiple gestures are sometimes used for the same purpose, perhaps conveying some not-yet-understood nuance.) Stomping two feet, for example, is used to initiate play. Reaching means, “I want that,” and an air-hug embrace is a request for contact.

Geocurrents’ Asya Pereltsvaig maps the origins of servicement in the American military. It turns out that saying that they come from red states is an oversimplification (among other things).

GNXP notes that the “aquatic ape” theory of human origins is accurate at least inasmuch as human populations, unlike chimpanzee populations, aren’t divided into separate subspecies by major rivers. (We can swim.)

Marginal Revolution starts a comment thread speculating as to how democracy might disappear from the world.

The Power and the Money’s Noel Maurer notes that Argentina isn’t going to follow the American precedent and start electing judges.

Charlie Stross wonders about the future of democracy inasmuch as party politics is declining while a meta Ruling Party takes over.

Science blogger Supernova Condensate is also going to blog about his experience as a scientist working in Japan.

Towleroad’s coverage of the news that two American cancer patients also infected with HIV were apparently cured of the latter via a bone marrow transplant is correct in noting that this provides clues for a cure.

Window on Eurasia suggests that terrorist threats against the Sochi Olympics in Russia by Chechens will lead to a tightening of Russian control over the North Caucasus.

Bag News Notes features multiple interesting brief photo essays: one about the downloadable gun; one about the woman miraculously rescued from the wreckage of the factory in Bangladesh; one about how modernism, done right, can be quite beautiful.

At Beyond the Beyond, Bruce Sterling links to a critique of the English words and terms used by European Union officials and to a description of the post-democratic “info-state”.

Dr Godelieve Kranendonk, a behavioural biologist leading the study at AAP, a rescue centre for animals in the Netherlands, told BBC News that the results had been astonishing.

“Suddenly, [the chimps] woke up. It was as if they were zombies in their enclosures and now they are happy, playing with each other. They are chimps again – that was really nice to see,” she told me.

[. . .]

Staff at the AAP sanctuary care for the animals until they die. They try to rehabilitate them so that they can live out their remaining years happily.

The chimps are fed a good diet of vegetables, have toys and plenty of space in which to play. But Dr Kranendonk found that the abnormal behaviour actually increased. It was as if the animals did not know how to cope with their new found freedom.

Dr Kranendonk decided to consult Martin Bruene, a professor of human psychiatric disorders at the University of Bochum, Germany. He prescribed a course of anti-depressants for five of the chimps.

All the animals had been used in medical experiments and were infected with Hepatitis C. “Willy” showed the least abnormal behaviour. “Tomas” and “Zorro”, on the other hand, would spend a third of their waking hours eating their own vomit.

“Iris” had lost so much weight from vomiting when she first came to the sanctuary that the staff thought she would die.

The most troubled though was “Kenny”, a small chimp who was constantly anxious that the others would attack him and spent much of his time screaming in terror.

The chimps were given SSRI (Selective Serotonin Reuptake Inhibitors), which is a class of anti-depressant similar to Prozac and is used to treat human patients for depression, anxiety disorder and obsessive compulsive disorder.

After six to eight weeks, the animals behaviour started improving. The abnormal behaviour declined and the chimps began to play together. After seven months, there was a vast difference.

[. . .]

The big question though is whether the effect lasts when the chimps are taken off the medication. The early indications are promising. The medication has been steadily reduced and there has been no adverse effect on the chimps’ behaviour.

Kenny himself decided that he did not want to take the anti-depressants anymore. His clownish behaviour has continued.

“It seems that while on the medication, the chimps learn to be chimps again,” said Dr Kranendonk. “And once they have learned that, they don’t need the medication any more.”

This news reported by Scientific American is good news, contingent of course on the chimpanzees being properly housed and cared for after the experiments are done.

The US National Institutes of Health (NIH) should dismantle a decades-old colony of 360 chimpanzees, retiring all but roughly 50 of the animals to a national sanctuary, the biomedical agency was told on 22 January in a long-awaited report.

The report, from a working group of external agency advisors, also counsels the NIH to end about half of 21 existing biomedical and behavioral experiments, saying they do not meet criteria established in a December, 2011 Institute of Medicine (IOM) report.

“Clearly there is going to be a reduction in the use of chimpanzees in research,” says working group co-chair Kent Lloyd, the associate dean for research at the School of Veterinary Medicine at the University of California, Davis.

The report says that the NIH should begin planning sanctuary housing for the retiring animals “immediately”, and that a colony of about 50 animals would be sufficient for future research. The report also sets high hurdles for new chimpanzee experiments in the future, calling for the establishment of an independent committee that would vet individual study proposals after they first pass routine NIH scientific review. In cases where the burden on the animals is high, the benefit to humanity should have to be “very high” to pass muster with the committee, says Daniel Geschwind, the other co-chair of the working group and a geneticist at the School of Medicine at the University of California, Los Angeles.

The report suggests that three of nine ongoing invasive experiments, involving immunology and infectious diseases, could continue, because they meet the IOM criteria. These require that a study be needed for public health; that no alternative animal model exists; that performing the study in humans would be unethical; and that the animals be maintained in socially and physically appropriate habitats. The report also says that eight of 13 behavioral or comparative genomics studies could be allowed to continue, but in some cases only conditionally — meaning that funding for these experiments could not be renewed without passing the independent committee review.

The working group — a subgroup of NIH’s Council of Councils, a trans-agency advisory body — was chartered by NIH director Francis Collins one year ago to advise the agency on how to implement the recommendations of the IOM report, which found that most chimpanzee research was not necessary. Its recommendations are not binding; Collins is expected to respond to them in late March, after a 60-day period of public comment. But they signal yet another significant step in an ongoing retrenchment. Last month, the agency announced that it will retire 110 chimpanzees to the national Chimp Haven sanctuary in Keithville, Louisiana, after they had been first slated to move to an active NIH-supported research centre in San Antonio, Texas.

Michael Balter’s ScienceNOW article highlights yet another commonality between humans and our nearest cousins, the chimpanzees. There’s some question regarding the findings, described elsewhere in the article, but the conclusions seem plausible.

When economists and psychologists want to test fairness in humans, they turn to the Ultimatum Game. Typically, one subject, called the “proposer,” is given a sum of money to divide with a “responder.” If the responder accepts the proposer’s offer, both are rewarded. But if the responder rejects the offer, both get nothing. Although results vary, human proposers usually offer about 40 percent to 50 percent of the money, and responders reject offers that are under 20 percent — even though they will end up with nothing for doing so. Researchers interpret both behaviors as evidence for a basic sense of fairness.

In 2007, a team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, tried the Ultimatum Game on chimps. In a simplified version of the game, the team gave the chimps set options about how to divvy up dishes of raisins, such as a 50-50 split or an 80-20 split. The proposer, in a cage next to that of the responder, made an offer by pulling a tray halfway toward the responder. The responder had to choose between pulling it the rest of the way so that both chimps could get the food or refusing to pull it at all, in which case both chimps got nothing. In contrast with humans, chimps rarely rejected offers of 20% of the food; they only rejected such tenders in experiments where the proposer had the additional choice of taking all of the food and leaving the responder with nothing. The team concluded that the responders would accept even the meanest split as long as they got something, suggesting that unlike humans, they were not offended by blatantly unfair offers.

Some researchers pounced on the study, however, suggesting that chimps couldn’t be expected to play fair given the conditions of their captivity, which had taught chimps that they had little control over how much they got to eat, or that they might not be able to understand the complicated tray-pulling apparatus.

To try to resolve the debate, a team led by primatologist Frans de Waal of Emory University in Atlanta has developed what it considers a more chimp-friendly version of the Ultimatum Game. In previous work, de Waal and his co-workers had established that chimps could be trained to exchange tokens for food. In the new study, published online this week in the Proceedings of the National Academy of Sciences, de Waal and his colleagues trained six chimps to recognize that such colored tokens, made of short pieces of plastic pipe, represented one of two ways of dividing six banana slices: an equal 3-3 split or an unequal 5-1 split (see video). The proposer chimp chose one of the tokens and then handed it through the wire mesh of its cage to a responder chimp, which had to give it to a human experimenter for both chimps to get the food. In essence, the tokens served as money that could be exchanged for the banana slices.

The chimps seemed to be playing fair. The percentage of equitable (3-3) offers ranged from 58% to 92%, much higher than in the Leipzig study which averaged about 25% for such 50-50 splits. However, as in the Leipzig study, the chimps never rejected “unfair” offers of 5-1 splits.

The team concluded that a sense of fairness arose sometime before the chimp and human lines split some 5 million to 7 million years ago, and that doing right by others has a long evolutionary history. “When we see this kind of behavior in humans, we call it fairness,” says the study’s lead author, psychologist Darby Proctor, now of Emory University, who adds that researchers shouldn’t “hesitate to call it fairness in chimps.”